


Most Powerful Harem in the World

by Anonymous



Category: One Piece
Genre: Body Modification, Brainwashing, Breeding, Collars, Evil Luffy, F/F, F/M, Forced Feminization, Gender or Sex Swap, Genderbending, Girls in Chains, Harems, Light BDSM, Mind Control, Mind Manipulation, Mindfuck, Pheromones, Porn With Plot, Rape/Non-con Elements, Rough Sex, Rule 63, Sexual Slavery, Sexual Violence, Smart Monkey D. Luffy, Superpower Sex
Language: English
Status: In-Progress
Published: 2018-05-06
Updated: 2018-05-06
Packaged: 2019-05-02 23:26:37
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Major Character Death, Rape/Non-Con
Chapters: 1
Words: 2,445
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14555874
Author URL: https://archiveofourown.org/
Summary: Luffy eats the Horm-Horm Fruit instead of the Gum-Gum. Forced to rely more on his brain growing up, and working with a very versatile power, he becomes a very different kind of person. His determination to become Pirate King hasn't wavered, but the means to get there have. Manipulative and self-indulgent, Luffy takes the seas by storm. He finds useful and powerful people, and then uses his complete control of human body to make himself irresistible, bend them to his will, turning them into beautiful women in the process, for the ones who weren't women already.Luffy's path to the end of the Grand Line relies less on luck, and now, on building the most powerful harem in the world.





	Most Powerful Harem in the World

"What's that smell?" Alvida muttered, blush rushing to her cheeks as she walked down to the lower level of her ship. There, two of her men, and Coby the cabin boy, were discussing a barrel. "Hey!"

"Captain Alvida!" all three snapped to attention, fear setting them straight. 

"What's going on here, then?" she barked, gesturing at the barrel.

"Uh, we found it floating in the water." one of the men said, "We were just about to open it up and see what's inside."

"...Open it." 

They didn't have to, however, as the top of the barrel burst open, and a handsome young man with a scar below his eye and a straw hat tied to him by a string, rose from it, stretching. "Ahhh~! What a good nap!"

"Wh-What the hell?!"

The man blinked at the sound of the voice, before turning towards Alvida. Grinning, he looked her up and down, before climbing out of the barrel. Alvida, for some reason, began to feel hot as he approached, breathing harder. She began to feel flustered, without knowing why. He held up his hand, pressing it against her chest, and she suddenly felt a sharp pinch. "Hey!" she protested, "What are you- ahhn!" 

"C-Captain!?" the two crew-men stared in awe as their captain began to shrink, steam rising off of her body. Or rather, Her face was flush, and she began to moan pleasurably as she leaned into the man who had turned his finger-tips into needles and pierced her. Soon, Alvida was in truth what she had always claimed to be. She was still on the heavier side, but now, her proportions were a bit more favorable to her. Pulling his hand free from her chest, the black-haired boy drew her mouth close to his. Kissing her deeply, he wrapped his arms around her, before letting her fall away. 

Hearts in her eyes, Alvida grinned stupidly at the man.

"Thank you for saving my life." he said, smiling back at her in a way that sent a shiver down her spine, "My name is Monkey D. Luffy. What's your name?"

"M-my name? It's Alvida." she said. 

"A beautiful name." Luffy said with a grin, "It fits you well. Are you a pirate?"

"Yes. I even have a bounty. You're on my ship, the _Miss Love Duck_. People around these parts know me as 'Iron Mace Alvida'."

"Impressive! How lucky for me." he praised, and she looked away, blushing, "Show me around the ship."

Coby stared, uncomprehending, as the woman who had tormented him for months, who kept her crew in a constant state of fear, followed the man who had literally popped out of the ocean like a schoolgirl with a crush. The two older men were having an even harder time coming to terms with this. 

* * *

 

It had all started when he was very young. A pirate, one whose strength he hadn't realized at the time, had come to stay at their village. Shanks had been many things to Luffy. A friend, a mentor, a role model, and most importantly, a catalyst.

It was Shanks who had placed the fruit on the bar, after all, even if he hadn't meant for Luffy to eat it.

That fruit changed the direction Luffy's life took from that moment on. The Horm-Horm Fruit wasn't suited to direct combat. While he did figure out ways to tweak his own body to make himself more powerful, heal faster, and fight harder, it wasn't the explosive edge that he had been hoping for. When he was eventually sent up to live in the mountains with the mountain bandits by his grandfather, he met another person who would change the direction of his life.

At first, Ace had been avoiding him. Letting Luffy get lost in the woods, and in doing so, he had forced the issue of survival upon the child. All at once, his power was a necessary tool, and he had to become creative in its use. He would pump himself with testosterone to fight off animals. Learn to erase or mimic the scents and pheromones of other animals to camouflage himself. He had learned how to expunge poisons from his own body, and how to create them as well. 

His power gave him the unique ability to utterly control body chemistry. He could change his appearance, his stature, his physical gender, his size, his bone structure, and could do the same in others. Eventually, he was able to follow Ace all the way through the jungle, able to use his abilities to match the older boy in strength, and to repel or take down the animals along the way. There, he met Sabo as well, and discovered that the two of them were planning on becoming pirates, gathering treasure. Through a series of misadventures, much of it painful, the two boys came to recognize Luffy as being trustworthy, and they became blood-brothers.

It was then that Luffy learned the potential of manipulating people. Being able to go into the same restaurant again and again, as he could change their appearance enough that the staff couldn't recognize them as thieves. Using pheromones and fine words to charm people into considering them trustworthy. 

When Bluejam and his crew moved to kidnap Sabo back to his rich parents, Luffy used his powers to save his brother. It was something that they did all the time, really, mainly as a disguise. He made Sabo into a girl, and his family never bothered him again. Bluejam, on the other hand, died from Luffy's cultivated toxins. 

The three of them enjoyed a long childhood, and once they hit puberty, they learned how to navigate women, together. This was another area where Luffy's abilities gave him an advantage. By fine-tuning his own pheromones, he could set women off from his simple presence, and if he could get in close, he could tweak their hormones to respond to him better than they ever would have normally. He could create an artificial lust far stronger than any natural one. 

It was... a bit underhanded, to be sure. But wasn't that part of being a pirate really? Taking what you want, no matter the method. So he embraced it. The Goa kingdom was a good place for an enterprising young man. There were any number of girls Luffy's age who wanted nothing more than to have a night of adventure away from their pampered lives with a young handsome rogue from the dark side of the capital. It was fun, it was good practice, and it also gave Ace and Sabo the opportunity to rob her place, just a little bit. 

Not to mention his body modification abilities were sought after, and nobles were willing to pay quite a bit to have him work his magic on them. Hormones that increase metabolism, cleared up skin, made them taller, grow their hair back, etc. 

The three siblings had been planning to set off together in the same ship, but the truth was that Luffy was more ambitious than the other two. He was going to be King of the Pirates, and that just wasn't compatible with Ace's natural role as the leader, and Sabo's role as the brains of the operation. Luffy wanted more than that. So he proposed a new plan. Ace and Sabo would set off together when they turned seventeen, and Luffy would go off on his own.

But in retrospect, Luffy saw the appeal of the original plan. Sabo was the only good navigator of the three of them, with Ace having maybe passable skills, and Luffy able to get lost on a straight line, on some days. 

As it was, after he left Windmill Village in a little fishing boat, he was caught in a whirlpool only a few days later. Sealing himself in a barrel was the first thing he thought of to try and get out of drowning. 

* * *

 

And now, he was in a perfect situation. A fully-stocked pirate ship, with a crew, and a captain who he has wrapped around his finger. Alvida, on her end, hadn't quite worked out anything was wrong. And with any luck, she wouldn't for a long while. It helped that she had been working under a delusion of her own. Her men praised her up and down upon fear of death, and she saw her own body as perfect- and it was, in many ways. Luffy had to train on a mountain for years to reach the level of strength needed to swing around a heavy iron mace like that. But it wasn't exactly what _most_ would consider beautiful. Although, now that he did a little work on her, she was shaping up quite nicely. Either way, his meddling with her body chemistry matched well with her delusions, and his interest in her seemed to her to be both perfectly normal, and deserved.

He had no doubt that he would be able to use Alvida for a long time. The real question was of whether or not he would be able to control others. Luffy had never tried to control someone for extended periods of time, after all, and he was looking forward to seeing how it would work. His plan wouldn't work well otherwise. 

One thing his power had taught him, was that using other people helped you do more than you could achieve yourself. He'd never dream of using Sabo or Ace, or even Dadan or his grandpa, or the people of Windmill Village, or Shanks and his crew.

But everyone else?

Well, he was a pirate. He would take what he wanted, including fighters. Ace and Sabo both had been stronger than he was, although by training with them in the mountains for years, he was a bit of a monster himself. But he was under no misconceptions. There were stronger monsters out there. And like the animals in the jungle, with his pheromones he would make them feel at ease, and with his powers he would take control of them, and turn their strength into his strength. 

He offered his hand, and flustered, Alvida took it, looking far too happy. He grinned back at her, and she looked away, overcome by girlish shyness that not one of her crew had ever seen from her before.

He would make her strength into his own strength. Her ship was his ship. Her crew was his, now. 

"So, Alvida dear?" he said sweetly, "Tell me about yourself. What ambitions do you hold?"

"Oh, nothing too special." she said, "I just want to live the way I want, I suppose. Eat good food, drink good drink, buy whatever I wish whenever I wish it! Murder anyone I feel like, and not face a single damn consequence~ It's why I became a pirate."

"I became a pirate for... similar reasons." he said, a bit nervously. Killing anyone she wanted was... a bit much. "I wanted to be the most free person in the world. Not a single rule or law that can contain me. I want to become the King of all the oceans of the world, the Pirate King." 

Her eyes sparkled at the genuine joy in his tone, and he smiled back at her, "Hey, Alvida, would you like to help me? Would you go to the Grand Line with me?"

"I'd love to!" she squealed, grabbing onto him and pulling him tight against her body. Grinning, Luffy began to increase the pheromones further, and Alvida practically drooled over him. Pulling away just enough, he began to lead her towards where she said her bedroom was, and she got the hint immediately, rushing for the bedroom. 

* * *

 

"Ahhn~! Haa! Haaah!" as he slid in and out of her, the woman below him moaned mindlessly, her senses gone in the face of the overwhelming biological need to breed he was pushing upon her. She clung close to him, pressing her breasts against his chest and shaking her hips along to his rhythm. 

Luffy smiled from his position over her as he pulled one hand away from where he was holding her against him to take her chin and guide her face to his. 

All in all, he had slept with a large number of women in Goa, but they all tended to be of the same breed. Young, foolish, girls who didn't have to work a day in their lives. He had to hold back with them, for fear of breaking their frail bodies as they fucked. But with Alvida, for the first time he was with a woman who was as strong as him. He went at full power, slamming her down into the bed, and she took it without a complaint. 

"H-harder!" she moaned, and he was left for a half-moment wondering if for once he wouldn't be able to satisfy. So, instead, he grew a needle from his finger, and injected himself. Pumping up his own adrenaline and other hormones to increase his strength and endurance, he began to sink into her anew, railing the pirate woman silly as she screamed in delight. Laughing, excited and enoying himself, he then jabbed her instead. All at once, pure, liquid pleasure was injected into her from two ends. The rush of hormones into her blood, being sent straight to her brain from his finger, and his cum sent into her waiting womb, soaked with a natural aphrodisiac he had concocted. 

She shuddered in orgasmic bliss, before fainting below him, her body going limp, beside the occasional shudders that wracked her form. Luffy pulled his finger away, and grinned triumphantly. Soon, he would have her quite literally addicted to him. His scent, his voice, his touch, and most importantly, his cum, it was all becoming entrenched in her brain as a necessity of life. 

Pulling free of the unconscious woman, Luffy leaned out of the bed, reaching for his jacket. In the pocket was a bundle of posters he had collected, and once more, he unrolled them. It was a list of individuals, some in the form of newspaper clippings, others wanted posters. He already knew what kind of crew he wanted to build. 

Two, more than anything else, jumped out at him. 

Roronoa Zoro, the Demon Swordsman, and Arlong, Captain of the Fish-Man pirates. 

All it would take was a single jab, and they would be his, just as Alvida was. A single touch, and two of the strongest men of East Blue would become women addicted to everything about him.

Along with Alvida, they would become part of his harem. The strongest harem in the world. The harem of the future Pirate King. 


End file.
